Medical lasers have been used in treatment procedures involving various practice areas including, for example, urology, neurology, otorhinolaryngology, general anesthetic ophthalmology, dentistry, gastroenterology, cardiology, gynecology, and thoracic and orthopedic procedures. Generally, these procedures require precisely controlled delivery laser energy, and often the area to which the energy is to be delivered is located deep within the body, for example, at the prostate or at the fallopian tubes. Due to the location of the target tissue deep within the body, the medical procedure generally requires use of a flexible and maneuverable optical fiber. Depending upon the requirements for a light source, a variety of light sources can be used in conjunction with the optical fiber including, for example, pulsed lasers, diode lasers, and neodymium lasers. Representative lasers used in medical treatment procedures include Ho:YAG lasers and Nd:YAG lasers.
In medical procedures utilizing laser energy, the laser is coupled to an optical fiber adapted to direct laser radiation from the laser, through the fiber and to the treatment area. Typically, a surgical probe is utilized in the treatment of body tissue with laser energy. The surgical probe generally includes an optical fiber coupled to a laser source, and the probe tip or cap is positioned on the optical fiber opposite the laser source, such that the cap of the probe can be positioned adjacent the targeted tissue. Laser energy is directed out of the probe cap of the optical fiber onto desired portions of the targeted tissue. The optical fiber and surgical probe cap deliver laser radiation to the treatment area on the tissue, wherein the laser radiation has a wavelength and has an irradiance in the treatment area sufficient to cause vaporization of a substantially greater volume of tissue than a volume of residual coagulated tissue caused by the laser radiation.
An optical fiber generally consists of a core surrounded by cladding, which in turn is surrounded by a buffer and a jacket. The cladding has a lower refractive index than the core does, and light travels along the fiber as a result of the difference in the indices of refraction of the core and cladding materials. Light is kept in the core of the optical fiber by internal reflection of light, thus causing the fiber to act as a waveguide. The jacket of the fiber is designed to protect the optical fiber during use and storage, and is generally made of a thin layer of material including, for example, metal, plastic, polyimide, nylon, or fluoropolymer.
The laser system can fail due to the failure of the optical fiber. In particular, the failure of a cap on a treatment of the optical fiber can cause the laser system to fail. Failure of the cap can require replacement of the optical fiber cap or the entire optical fiber. Failure of the cap is especially critical if it occurs during treatment and pieces of the failed optical fiber must be flushed out or picked out of the patient and a new optical fiber must be installed. Further, failure of the cap can complicate performance of the procedure, delay performance of the scheduled medical procedure, and raise operating costs due to delay and the need for replacement parts. Hence, there remains a need for preventing failure of the laser system and, in particular, of the optical fiber.